This invention relates generally to the enhancement of aircraft design, primarily in the unmanned aircraft vehicle (UAV) domain. UAV design recently has taken several forms and appearances with corresponding applications and implementations.
Fixed wing UAV aircraft are primarily built around a ground parallel fuselage traversing the length of the aircraft implementing fixed or blended parallel surfaces with respect to the aircraft in order to provide a perpendicular force or lift. The aircraft is then provided forward thrust by a propulsive device using compressor/turbine power, propeller power, or a combination/hybrid of each.
Traditional fixed wing UAV aircraft are controlled in flight using a series of moving surfaces denoted as the aileron, elevator, and rudder, each attached to different locations of the aircraft. The aileron is attached to the primary lifting surface, elevators attached to the secondary lifting surface, and rudder attached to the vertical tail. Some blended wing UAV aircraft such as the Lockheed martin rq-170 sentinel drone implement split flaps inducing surface specific drag rather than a vertical tail. Fixed wing UAV aircraft provide efficient, multi-range, reliable methods of surveillance and military designated missions.
Rotorcraft UAV aircraft are primarily built around a series of rotating blades compromised in a single rotor hub or multi rotor hub system. Single rotor hub aircraft synthesize the lifting and thrust components into a single source and its vector controlled by a swash plate and series of bar linkages to determine the orientation of the aircraft. Additionally pitch angle of the blades can be controlled in order to determine the magnitude of the lifting and thrust vector. The angular momentum of the primary blade is then offset by a counter rotating secondary tail blade and connected through a gearbox and/or transmission system to the primary blade. The yaw orientation of the aircraft is controlled by the pitch angle of the secondary counter-rotating blade.
Multi rotor hub UAV aircraft such as a quad-copter or octo-copter at current time maintain a constant blade pitch angle and employ differential angular velocities per rotor hub in order to maneuver roll, pitch, and yaw orientation the aircraft. Vertical motion is controlled simply by available power to each rotor hub. The primary benefit of rotorcraft-implemented device is the vertical take off and landing (VTOL) aspect. The primary adverse effect of large rotorcraft vehicles is overcoming transonic blade tip speeds, which limits forward flight speeds.
Hybrid UAV aircraft synthesize both a primary lifting winged surface and a variable vector thrust in order to achieve VTOL and efficient cruise performance. The design and appearance of these vehicles is extensive and conceptual domain endless. Most designs however incorporate a tilt rotor feature employing either single or dual ducted/unducted fans, which are either covered or exposed during, forward flight.
The application for such UAV aircraft designs is under constant exploration and optimization. Current applications for UAV aircraft are military designated reconnaissance, government, industrial/geological surveillance, and hobby enthusiasts. Applications under consideration and future applications may include but are not limited to courier shipping, agriculture surveillance, and medical transport. Currently the FAA is set to rule on regulations and limitations of domestic UAV employment and should be stated within the end of 2014.